Add finance bias evaluator

[Tibo2403]

Summary

• Add a deterministic Python evaluator for finance security and algorithmic-bias review prompts.
• Enforce the requested strict JSON schema: statut, confiance, justification_technique.
• Detect risky patterns such as protected attributes/proxies, fully automated financial decisions, opaque systems, exposed secrets, unsupported guarantees, hallucinated helper functions, and indirect financial exclusion.
• Add documentation with usage examples and limitations.

Validation

• python -m py_compile /mnt/data/finance_bias_evaluator.py
• Valid sample returns statut: 1.
• Risky sample with age/zip code/auto-approval returns statut: 0.
• Empty input returns statut: 0.

Note: this is a static first-pass guardrail, not a formal proof of fairness or security.